Studies in Progress or Projected: (1) Characterization of the purified prolyl hydroxylase from earthworm subcuticular epithelium; (2) Excretion of total and free 3-hydroxyproline in human urine; (3) Peptide distribution of urinary 3-hydroxyproline; (4) Hydroxylation of prolyl residues in basement membrane collagen; (5) Synthesis and properties of collagen-like polypeptides containing proline, 4-hydroxyproline and/or 3-hydroxyproline. BIBLIOGRAPHIC REFERENCES: Blass, D.A., and Adams, E. Polarimetry as a General Method for Enzyme Assays. Anal. Biochem. 71, 405-414 (1976). Rao, N.V. Kinetic Studies of Earthworm Subcuticular Prolyl Hydroxylase. Fed. Proc. 36, 753 (1977).